The incidence of diabetes among 0-34 year olds in Sweden: new data and better methods

The Development of the Municipal Registry of People with Diabetes in Porto Alegre, Brazil

Background/Objective: Diabetes registries that enhance surveillance and improve medical care are uncommon in low- and middle-income countries, where most of the diabetes burden lies. We aimed to describe the methodological and technical aspects adopted in the development of a municipal registry of people with diabetes using local and national Brazilian National Health System databases. Methods: We obtained data between July 2018 and June 2021 based on eight databases covering primary care, specialty and emergency consultations, medication dispensing, outpatient exam management, hospitalizations, and deaths. We identified diabetes using the International Classification of Disease (ICD), International Classification of Primary Care (ICPC), medications for diabetes, hospital codes for the treatment of diabetes complications, and exams for diabetes management. Results: After data processing and database merging using deterministic and probabilistic linkage, we identified 73,185 people with diabetes. Considering that 1.33 million people live in Porto Alegre, the registry captured 5.5% of the population. Conclusions: With additional data processing, the registry can reveal information on the treatment and outcomes of people with diabetes who are receiving publicly financed care in Porto Alegre. It will provide metrics for epidemiologic surveillance, such as the incidence, prevalence, rates, and trends of complications and causes of mortality; identify inadequacies; and provide information. It will enable healthcare providers to monitor the quality of care, identify inadequacies, and provide feedback as needed.

Incident Cardiovascular Disease in Women With Type 1 or Type 2 Diabetes Following a Hypertensive Disorder of Pregnancy

BACKGROUND

The extent to which a history of hypertensive disorders of pregnancy is associated with incident cardiovascular disease also among women with diabetes is unknown.

METHODS

In this nationwide register-based cohort study, parous women aged 18 to 69 years with a first delivery in the Swedish Medical Birth Register, regardless of diabetic status at that time, and a subsequent clinical visit in the Swedish National Diabetes Register were included. Time to first cardiovascular disease event (myocardial infarction, stroke, or heart failure) before age 70 years by hypertensive disorders of pregnancy history was separately analyzed by diabetes type using Cox regression models that included conventional risk factors.

RESULTS

In total, 1748 (18.9%) of 9230 women with type 1 and 5904 (10.6%) of 55 773 women with type 2 diabetes had their first delivery complicated by a hypertensive disorder of pregnancy. Median time (25-75th percentile) between first delivery and start of follow-up was 3.3 (1.4-13.0) years for women with type 1 and 29.8 (22.4-35.6) years for women with type 2 diabetes. In modeling, the risk for any cardiovascular disease event among women with a history of hypertensive disorders of pregnancy was generally 10% to 20% higher, with main models estimating hazard ratios to 1.20 (95% CI, 0.99-1.47) for women with type 1 and 1.15 (95% CI, 1.02-1.29) for women with type 2 diabetes.

CONCLUSIONS

In women with diabetes, a history of hypertensive disorders of pregnancy was associated with an increased risk of incident cardiovascular disease and should be considered as a risk enhancer.

A Review on Latent Autoimmune Diabetes in Adults

Latent autoimmune diabetes (LADA) is an unique form of diabetes that has characteristics of both type 1 and type 2 diabetes. Type 1.5 diabetes also known as LADA is occasionally confused for type 2 diabetes because there is delay in presenting features and early insulin independence. LADA, on the other hand, is an autoimmune disorder that differs from type 2 diabetes in that autoantibodies against pancreatic beta cells are what characterise it. Insulin production eventually diminishes due to the autoimmune destruction of pancreatic beta cells as a result of the pathophysiology of LADA. Autoantibodies to glutamic acid decarboxylase (GAD), islet antigen-2 (IA-2), and insulin are frequently detected in LADA patients. These autoantibodies have important implications for therapy strategies and are essential in differentiating LADA from type 2 diabetes. LADA clinical management is very challenging. The aim of this article is to view the characteristics, disease presentation, diagnostic challenges, progression and treatment modalities of LADA.

Validation of Register-Based Diabetes Classifiers in Danish Data

Purpose

To validate two register-based algorithms classifying type 1 (T1D) and type 2 diabetes (T2D) in a general population using Danish register data.

Patients and Methods

After linking data on prescription drug usage, hospital diagnoses, laboratory results and diabetes-specific healthcare services from nationwide healthcare registers, diabetes type was defined for all individuals in Central Denmark Region age 18-74 years on 31 December 2018 according to two distinct register-based classifiers: 1) a novel register-based diabetes classifier incorporating diagnostic hemoglobin-A1C measurements, the Open-Source Diabetes Classifier (OSDC), and 2) an existing Danish diabetes classifier, the Register for Selected Chronic Diseases (RSCD). These classifications were validated against self-reported data from the Health in Central Denmark survey - overall and stratified by age at onset of diabetes. The source-code of both classifiers was made available in the open-source R package osdc.

Results

A total of 2633 (9.0%) of 29,391 respondents reported having any type of diabetes, divided across 410 (1.4%) self-reported cases of T1D and 2223 (7.6%) cases of T2D. Among all self-reported diabetes cases, 2421 (91.9%) were classified as diabetes cases by both classifiers. In T1D, sensitivity of OSDC-classification was 0.773 [95% CI 0.730-0.813] (RSCD: 0.700 [0.653-0.744]) and positive predictive value (PPV) 0.943 [0.913-0.966] (RSCD: 0.944 [0.912-0.967]). In T2D, sensitivity of OSDC-classification was 0.944 [0.933-0.953] (RSCD: 0.905 [0.892-0.917]) and PPV 0.875 [0.861-0.888] (RSCD: 0.898 [0.884-0.910]). In age at onset-stratified analyses of both classifiers, sensitivity and PPV were low in individuals with T1D onset after age 40 and T2D onset before age 40.

Conclusion

Both register-based classifiers identified valid populations of T1D and T2D in a general population, but sensitivity was substantially higher in OSDC compared to RSCD. Register-classified diabetes type in cases with atypical age at onset of diabetes should be interpreted with caution. The validated, open-source classifiers provide robust and transparent tools for researchers.

Maternal depression or anxiety during pregnancy and offspring type 1 diabetes: a population-based family-design cohort study

INTRODUCTION

To investigate the association between maternal depression/anxiety during pregnancy and offspring type 1 diabetes, to assess the specific importance of exposure during pregnancy by comparing across different exposure periods before and/or after pregnancy, and to explore potential unmeasured familial confounding.

RESEARCH DESIGN AND METHODS

This was a population-based cohort including 1 807 809 offspring born in Sweden 2002-2019. From national registers, data were available on diagnosis or medication prescription for depression/anxiety in and around pregnancy, as well as incident cases of type 1 diabetes defined through diagnosis or insulin treatment. Associations were examined using flexible parametric and Cox regression models. Familial confounding was explored using paternal exposure as a negative control and by comparing offspring exposed to maternal depression/anxiety with their unexposed siblings.

RESULTS

For exposure during pregnancy, maternal depression/anxiety was associated with an increased risk of offspring type 1 diabetes onset after, but not before, 8 years of age (adjusted HR (aHR) 1.21 (95% CI 1.03 to 1.42]). Exposure occurring only during pregnancy was similarly associated to type 1 diabetes (aHR 1.24 (0.96 to 1.60)), whereas exposure occurring only before pregnancy was not (aHR 0.91 (0.64 to 1.30)). Associations were close to the null for paternal depression/anxiety (aHR 0.95 (0.72 to 1.25)), and point estimates were above 1 in sibling comparisons, although with wide CIs (aHR 1.36 (0.82 to 2.26)).

CONCLUSIONS

Maternal depression/anxiety specifically during pregnancy seems to be associated with offspring type 1 diabetes. Paternal negative control and sibling comparisons indicate that the results cannot entirely be explained by familial confounding.

Predicting misdiagnosed adult-onset type 1 diabetes using machine learning

AIMS

It is now understood that almost half of newly diagnosed cases of type 1 diabetes are adult-onset. However, type 1 and type 2 diabetes are difficult to initially distinguish clinically in adults, potentially leading to ineffective care. In this study a machine learning model was developed to identify type 1 diabetes patients misdiagnosed as type 2 diabetes.

METHODS

In this retrospective study, a machine learning model was developed to identify misdiagnosed type 1 diabetes patients from a population of patients with a prior type 2 diabetes diagnosis. Using Ambulatory Electronic Medical Records (AEMR), features capturing relevant information on age, demographics, risk factors, symptoms, treatments, procedures, vitals, or lab results were extracted from patients' medical history.

RESULTS

The model identified age, BMI/weight, therapy history, and HbA1c/blood glucose values among top predictors of misdiagnosis. Model precision at low levels of recall (10 %) was 17 %, compared to <1 % incidence rate of misdiagnosis at the time of the first type 2 diabetes encounter in AEMR.

CONCLUSIONS

This algorithm shows potential for being translated into screening guidelines or a clinical decision support tool embedded directly in an EMR system to reduce misdiagnosis of adult-onset type 1 diabetes and implement effective care at the outset.

Associations between deduced first islet specific autoantibody with sex, age at diagnosis and genetic risk factors in young children with type 1 diabetes

OBJECTIVES

We aimed to further characterize demography and genetic associations of type 1 diabetes "endotypes" defined by the first appearing islet specific autoantibodies.

RESEARCH DESIGN AND METHODS

We analyzed 3277 children diagnosed before the age of 10 years from the Finnish Pediatric Diabetes Register. The most likely first autoantibody could be deduced in 1636 cases (49.9%) based on autoantibody combinations at diagnosis. Distribution of age, sex, HLA genotypes and allele frequencies of 18 single nucleotide polymorphisms (SNPs) in non-HLA risk genes were compared between the endotypes.

RESULTS

Two major groups with either glutamic acid decarboxylase (GADA) or insulin autoantibodies (IAA) as the deduced first autoantibody showed significant differences in their demographic and genetic features. Boys and children diagnosed at young age had more often IAA-initiated autoimmunity whereas GADA-initiated autoimmunity was observed more frequently in girls and in subjects diagnosed at an older age. IAA as the first autoantibody was also most common in HLA genotype groups conferring high-disease risk while GADA first was seen more evenly and frequently in HLA groups associated with lower type 1 diabetes risk. The risk alleles in IKZF4 and ERBB3 genes were associated with GADA-initiated whereas those in PTPN22, INS and PTPN2 genes were associated with IAA-initiated autoimmunity.

CONCLUSIONS

The results support the assumption that in around half of the young children the first autoantibody can be deduced based on islet autoantibody combinations at disease diagnosis. Strong differences in sex and age distributions as well as in genetic associations could be observed between GADA- and IAA-initiated autoimmunity.

Fruit and vegetable intake and risk of prediabetes and type 2 diabetes: results from a 20-year long prospective cohort study in Swedish men and women

Purpose

To investigate the association between fruit and vegetable intake (FVI) and the risk of developing prediabetes and type 2 diabetes (T2D) in a Swedish prospective cohort study.

Methods

Subjects were 6961 men and women aged 35–56 years old at baseline, participating in the Stockholm Diabetes Prevention Program cohort. By design, the cohort was enriched by 50% with subjects that had family history of diabetes. Anthropometric measurements, oral glucose tolerance tests and questionnaires on lifestyle and dietary factors were carried out at baseline and two follow-up occasions. Cox proportional hazard models were used to estimate hazard ratios with 95% CIs.

Results

During a mean follow-up time of 20 ± 4 years, 1024 subjects developed T2D and 870 prediabetes. After adjustments for confounders, the highest tertile of total FVI was associated with a lower risk of developing T2D in men (HR 0.76, 95% CI 0.60–0.96). There was also an inverse association between total fruit intake and prediabetes risk in men, with the HR for the highest tertile being 0.76 (95% CI 0.58–1.00). As for subtypes, higher intake of apples/pears was inversely associated with T2D risk in both sexes, whereas higher intakes of banana, cabbage and tomato were positively associated with T2D or prediabetes risk in either men or women.

Conclusion

We found an inverse association between higher total FVI and T2D risk and between higher fruit intake and prediabetes risk, in men but not in women. Certain fruit and vegetable subtypes showed varying results and require further investigation.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00394-022-02871-6.

The Incidence of Adult-Onset Type 1 Diabetes: A Systematic Review From 32 Countries and Regions

BACKGROUND

The epidemiology of adult-onset type 1 diabetes (T1D) incidence is not well-characterized due to the historic focus on T1D as a childhood-onset disease.

PURPOSE

We assess the incidence of adult-onset (≥20 years) T1D, by country, from available data.

DATA SOURCES

A systematic review of MEDLINE, Embase, and the gray literature, through 11 May 2021, was undertaken.

STUDY SELECTION

We included all population-based studies reporting on adult-onset T1D incidence and published from 1990 onward in English.

DATA EXTRACTION

With the search we identified 1,374 references of which 46 were included for data extraction. Estimates of annual T1D incidence were allocated into broad age categories (20-39, 40-59, ≥60, or ≥20 years) as appropriate.

DATA SYNTHESIS

Overall, we observed the following patterns: 1) there is a paucity of data, particularly in low- and middle-income countries; 2) the incidence of adult-onset T1D is lowest in Asian and highest in Nordic countries; 3) adult-onset T1D is higher in men versus women; 4) it is unclear whether adult-onset T1D incidence declines with increasing age; and 5) it is unclear whether incidence of adult-onset T1D has changed over time.

LIMITATIONS

Results are generalizable to high-income countries, and misclassification of diabetes type cannot be ruled out.

CONCLUSIONS

From available data, this systematic review suggests that the incidence of T1D in adulthood is substantial and highlights the pressing need to better distinguish T1D from T2D in adults so that we may better assess and respond to the true burden of T1D in adults.

Alterations in Biomarkers Related to Glycemia, Lipid Metabolism, and Inflammation up to 20 Years Before Diagnosis of Type 1 Diabetes in Adults: Findings From the AMORIS Cohort

OBJECTIVE

Type 1 diabetes is described to have an acute onset, but autoantibodies can appear several years preceding diagnosis. This suggests a long preclinical phase, which may also include metabolic parameters. Here we assessed whether elevations in glycemic, lipid, and other metabolic biomarkers were associated with future type 1 diabetes risk in adults.

RESEARCH DESIGN AND METHODS

We studied 591,239 individuals from the Swedish AMORIS cohort followed from 1985-1996 to 2012. Through linkage to national patient, diabetes, and prescription registers, we identified incident type 1 diabetes. Using Cox regression models, we estimated hazard ratios for biomarkers at baseline and incident type 1 diabetes. We additionally assessed trajectories of biomarkers during the 25 years before type 1 diabetes diagnosis in a nested case-control design.

RESULTS

We identified 1,122 type 1 diabetes cases during follow-up (average age of patient at diagnosis: 53.3 years). The biomarkers glucose, fructosamine, triglycerides, the ratio of apolipoprotein (apo)B to apoA-I, uric acid, alkaline phosphatase, and BMI were positively associated with type 1 diabetes risk. Higher apoA-I was associated with lower type 1 diabetes incidence. Already 15 years before diagnosis, type 1 diabetes cases had higher mean glucose, fructosamine, triglycerides, and uric acid levels compared with control subjects.

CONCLUSIONS

Alterations in biomarker levels related to glycemia, lipid metabolism, and inflammation are associated with clinically diagnosed type 1 diabetes risk, and these may be elevated many years preceding diagnosis.

Comparison between data-driven clusters and models based on clinical features to predict outcomes in type 2 diabetes: nationwide observational study

AIMS/HYPOTHESIS

Research using data-driven cluster analysis has proposed five novel subgroups of diabetes based on six measured variables in individuals with newly diagnosed diabetes. Our aim was (1) to validate the existence of differing clusters within type 2 diabetes, and (2) to compare the cluster method with an alternative strategy based on traditional methods to predict diabetes outcomes.

METHODS

We used data from the Swedish National Diabetes Register and included 114,231 individuals with newly diagnosed type 2 diabetes. k-means clustering was used to identify clusters based on nine continuous variables (age at diagnosis, HbA_1c, BMI, systolic and diastolic BP, LDL- and HDL-cholesterol, triacylglycerol and eGFR). The elbow method was used to determine the optimal number of clusters and Cox regression models were used to evaluate mortality risk and risk of CVD events. The prediction models were compared using concordance statistics.

RESULTS

The elbow plot, with values of k ranging from 1 to 10, showed a smooth curve without any clear cut-off points, making the optimal value of k unclear. The appearance of the plot was very similar to the elbow plot made from a simulated dataset consisting only of one cluster. In prediction models for mortality, concordance was 0.63 (95% CI 0.63, 0.64) for two clusters, 0.66 (95% CI 0.65, 0.66) for four clusters, 0.77 (95% CI 0.76, 0.77) for the ordinary Cox model and 0.78 (95% CI 0.77, 0.78) for the Cox model with smoothing splines. In prediction models for CVD events, the concordance was 0.64 (95% CI 0.63, 0.65) for two clusters, 0.66 (95% CI 0.65, 0.67) for four clusters, 0.77 (95% CI 0.77, 0.78) for the ordinary Cox model and 0.78 (95% CI 0.77, 0.78) for the Cox model with splines for all variables.

CONCLUSIONS/INTERPRETATION

This nationwide observational study found no evidence supporting the existence of a specific number of distinct clusters within type 2 diabetes. The results from this study suggest that a prediction model approach using simple clinical features to predict risk of diabetes complications would be more useful than a cluster sub-stratification.

The Multifactorial Progression from the Islet Autoimmunity to Type 1 Diabetes in Children

Type 1 Diabetes (T1D) results from autoimmune destruction of insulin producing pancreatic ß-cells. This disease, with a peak incidence in childhood, causes the lifelong need for insulin injections and necessitates careful monitoring of blood glucose levels. However, despite the current insulin therapies, it still shortens life expectancy due to complications affecting multiple organs. Recently, the incidence of T1D in childhood has increased by 3-5% per year in most developed Western countries. The heterogeneity of the disease process is supported by the findings of follow-up studies started early in infancy. The development of T1D is usually preceded by the appearance of autoantibodies targeted against antigens expressed in the pancreatic islets. The risk of T1D increases significantly with an increasing number of positive autoantibodies. The order of autoantibody appearance affects the disease risk. Genetic susceptibility, mainly defined by the human leukocyte antigen (HLA) class II gene region and environmental factors, is important in the development of islet autoimmunity and T1D. Environmental factors, mainly those linked to the changes in the gut microbiome as well as several pathogens, especially viruses, and diet are key modulators of T1D. The aim of this paper is to expand the understanding of the aetiology and pathogenesis of T1D in childhood by detailed description and comparison of factors affecting the progression from the islet autoimmunity to T1D in children.

The burden of poor glycaemic control in people with newly diagnosed type 2 diabetes in Sweden: A health economic modelling analysis based on nationwide data

AIM

To evaluate the economic and clinical burden associated with poor glycaemic control in Sweden, in people with type 2 diabetes (T2D) initiating first-line glucose-lowering therapy.

MATERIALS AND METHODS

Population data were obtained from Swedish national registers. Immediate glycaemic control was compared with delays in achieving control of 1 and 3 years, with outcomes projected over 3, 10 and 50 years in the validated IQVIA CORE Diabetes Model. Glycaemic control was defined as glycated haemoglobin (HbA1c) targets of 52, 48 and 42 mmol/mol, as recommended in Swedish guidelines, according to age and disease duration. Costs (expressed in 2019 Swedish krona [SEK]) were accounted from a Swedish societal perspective.

RESULTS

Immediate glycaemic control was associated with population-level cost savings of up to SEK 279 million and SEK 673 million versus delays of 1 and 3 years, respectively, as well as small population-level life expectancy benefits of up to 1305 and 2590 life years gained. Reduced levels of burden were a result of lower incidence and delayed time to onset of diabetes-related complications.

CONCLUSIONS

Even in people with T2D initiating first-line glucose-lowering therapy, the economic burden of poor glycaemic control in Sweden is substantial, but could be reduced by early and effective treatment to achieve glycaemic targets.

Auto-immunity and the gut microbiome in type 1 diabetes: Lessons from rodent and human studies

Type 1 diabetes (T1D) is an auto-immune disease that destructs insulin-producing pancreatic beta-cells within the islets of Langerhans. The incidence of T1D has tripled over the last decades, while the pathophysiology of the disease is still largely unknown. Currently, there is no cure for T1D. The only treatment option consists of blood-glucose regulation with insulin injections and intensive monitoring of blood glucose levels. In recent years, perturbations in the ecosystem of the gut microbiome also referred to as dysbiosis, have gained interest as a possible contributing factor in the development of T1D. Changes in the microbiome seem to occur before the onset of T1D associated auto-antibodies. Furthermore, rodent studies demonstrate that administering antibiotics at a young age may accelerate the onset of T1D. This review provides an overview of the research performed on the epidemiology, pathophysiology, interventions, and possible treatment options in the field of the gut microbiome and T1D.

Cardiovascular and Renal Disease Burden in Type 1 Compared With Type 2 Diabetes: A Two-Country Nationwide Observational Study

OBJECTIVE

Type 1 diabetes (T1D) and type 2 diabetes (T2D) increase risks of cardiovascular (CV) and renal disease (CVRD) compared with diabetes-free populations. Direct comparisons between T1D and T2D are scarce. We examined this by pooling full-population cohorts in Sweden and Norway.

RESEARCH DESIGN AND METHODS

A total of 59,331 patients with T1D and 484,241 patients with T2D, aged 18-84 years, were followed over a mean period of 2.6 years from 31 December 2013. Patients were identified in nationwide prescribed drug and hospital registries in Norway and Sweden. Prevalence and event rates of myocardial infarction (MI), heart failure (HF), stroke, chronic kidney disease (CKD), all-cause death, and CV death were assessed following age stratification in 5-year intervals. Cox regression analyses were used to estimate risk.

RESULTS

The prevalence of CV disease was similar in T1D and T2D across age strata, whereas CKD was more common in T1D. Age-adjusted event rates comparing T1D versus T2D showed that HF risk was increased between ages 65 and 79 years, MI between 55 and 79 years, and stroke between 40 and 54 years (1.3-1.4-fold, 1.3-1.8-fold, and 1.4-1.7-fold, respectively). CKD risk was 1.4-3.0-fold higher in T1D at all ages. The all-cause death risk was 1.2-1.5-fold higher in T1D at age >50 years, with a similar trend for CV death.

CONCLUSIONS

Adult patients with T1D compared with those with T2D had an overall greater risk of cardiorenal disease (HF and CKD) across ages, MI and all-cause death at middle-older ages, and stroke at younger ages. The total age-adjusted CVRD burden and risks were greater among patients with T1D compared with those with T2D, highlighting their need for improved prevention strategies.

Faecal microbiota transplantation in endocrine diseases and obesity

The prevalence of type 1 (T1D) and type 2 diabetes mellitus (T2D) has greatly increased worldwide over the last century. Although the exact pathophysiology of both these conditions is distinct and still largely unknown, T1D as well as T2D, have been linked to distinct perturbations of the gut microbiome. Faecal microbiota transplantation (FMT) is a potent, and if performed well, a safe method to modulate the composition of the gut microbiome and thus positively influences the course of these hyperglycaemic conditions in humans. In this review, we provide an overview of how FMT is commonly performed and summarise how this procedure may reduce the insulin-resistance driving T2D, and the underlying auto-immunity driving T1D. Insights derived from FMT studies in T1D and T2D may help identify beneficial microbiota and associated metabolites that may serve as future treatments for these conditions.

Type 1 diabetes in children born after assisted reproductive technology: a register-based national cohort study

STUDY QUESTION

Do children born after assisted reproductive technology (ART) have an increased risk of developing type 1 diabetes?

SUMMARY ANSWER

Children born after ART were found to have an increased risk of type 1 diabetes in the unadjusted analysis, while after adjustment this association was only significant in children born after frozen embryo transfer.

WHAT IS KNOWN ALREADY?

Some studies raise concerns as to whether fertility treatments may influence long-term morbidity in children born after ART. Elevated blood pressure and altered glucose metabolism have been found after ART in a few studies.

STUDY DESIGN, SIZE, DURATION

A register-based national cohort study that included all children born in Sweden between 1985 and 2015-in total, 3 138 540 children-was carried out.

PARTICIPANTS/MATERIAL, SETTING, METHODS

The study was population-based and all live-born singleton children born after ART (n = 47 938) or spontaneous conception (SC) (n = 3 090 602) were included. The ART cohort comprised 36 727 children born after fresh embryo transfer and 11 211 children born after frozen embryo transfer. Several national registries were used together with data from Statistics Sweden.

MAIN RESULTS AND THE ROLE OF CHANCE

In total, 202 children born after ART and 17 916 children born after SC developed type 1 diabetes, corresponding to 43.4 and 35.5 per 100 000 person-years at risk (hazard ratio [HR] 1.23; 95% confidence interval [CI], 1.07 to 1.42). Mean follow-up was 9.7 (SD 6.4) years for ART children and 16.3 (SD 9.2) years for SC children. After adjustment for calendar year of birth, HR for type 1 diabetes was 1.13; 95% CI, 0.98-1.30. After further adjustment for sex, maternal age, country of birth, educational level, smoking and parental diabetes, HR was 1.07; 95% CI, 0.93-1.23. In subgroup analyses, an association was found between frozen embryo transfer and type 1 diabetes (adjusted HR 1.52; 95% CI, 1.08-2.14 and 1.41; 95% CI, 1.05-1.89 for frozen versus fresh and frozen versus SC, respectively). When comparing intracytoplasmic sperm injection to in vitro fertilization, no difference was found (adjusted HR 1.08; 95% CI, 0.77-1.51).

LIMITATIONS, REASONS FOR CAUTION

Limitations were the missing data and residual confounding caused by unknown confounders. Furthermore, the control group consisted of all children not conceived by ART and not non-ART children from subfertile mothers. The study was also performed in only singletons and not in the total ART population.

WIDER IMPLICATIONS OF THE FINDINGS

Type 1 diabetes is a serious disease, affecting human life in several ways, including risk of serious complications, reduced life span and a life-long treatment. Our results are generally reassuring, showing no increase in diabetes in ART children compared to children born after SC after adjustment for relevant confounders. The observation of an association between children born after frozen embryo transfer and type 1 diabetes, although based on subgroup analyses with a limited number of children and modest in size, is however a reason for concern.

STUDY FUNDING/COMPETING INTEREST(S)

This study was funded by Nordforsk 71450, the Swedish state under the agreement between the Swedish government and the county councils, the ALF-agreement 70940, and the Hjalmar Svensson Foundation. The authors have no competing interests.

TRIAL REGISTRATION NUMBER

ISRCTN 11780826.

Adherence to oral glucose tolerance testing in children in stage 1 of type 1 diabetes: The TEDDY study

OBJECTIVE

To examine adherence to the oral glucose tolerance test (OGTT) in multiple islet autoantibody children in stage 1 of developing type 1 diabetes (T1D).

METHODS

Children are followed from birth in The Environmental Determinants of Diabetes in the Young (TEDDY) study. Completion of an OGTT is recommended every 6 months in children ≥3 years of age who are multiple islet autoantibody positive. Factors associated with adherence to the OGTT protocol were examined.

RESULTS

The average subject level adherence with the OGTT protocol was 62% although there were large differences across countries; Finnish participants and older children from Sweden were more adherent than participants from the United States and Germany. Factors associated with nonadherence included having a first-degree relative with T1D, using a local laboratory rather than a TEDDY center for the OGTT, and maternal underestimation of the child's risk for T1D. Children were more adherent to the OGTT if their mothers: were more satisfied with TEDDY participation, reported monitoring the child for T1D by checking blood glucose levels at home, and viewed participating in TEDDY as the primary way they were monitoring the child for T1D.

CONCLUSIONS

In a study of children in stage 1 of T1D, adherence to an OGTT protocol was suboptimal despite extensive efforts to communicate the child's high risk to parents. These findings provide important guidance for development of strategies to improve methods for detecting progression or the development of T1D in high-risk pediatric populations.

National diabetes registries: do they make a difference?

AIMS

The global epidemic of diabetes mellitus continues to expand, including its large impact on national health care. Measuring diabetes outcomes and their causes of variation highlights areas for improvement in care and efficiency gains; large registries carry this potential. By means of a systematic review, we aimed to give an overview of national registries worldwide by quantifying their data and assessing their influence on diabetes care.

METHODS

The literature on MEDLINE up to March 31, 2020, was searched, using keywords diabetes mellitus, national, registry, registration, and/or database. National disease-specific registries from corresponding articles were included. Database characteristics and clinical variables were obtained. All registries were compared to the ICHOM standard set of outcomes.

RESULTS

We identified 12 national clinical diabetes registries, comprising a total of 7,181,356 diabetic patients worldwide. Nearly all registries recorded weight, HbA1c, lipid profile, and insulin treatment; the recording of other variables varied to a great extent. Overall, registries corresponded fairly well with the ICHOM set. Most registries proved to monitor and improve the quality of diabetes care using guidelines as a benchmark. The effects on national healthcare policy were more variable and often less clear.

CONCLUSIONS

National diabetes registries confer clear insights into diagnostics, complications, and treatment. The extent to which registries influenced national healthcare policy was less clear. A globally implemented standard outcome set has the potential to improve concordance between national registries, enhance the comparison and exchange of diabetes outcomes, and allocate resources and interventions where most needed.

Duration of diabetes-related complications and mortality in type 1 diabetes: a national cohort study

BACKGROUND

People with type 1 diabetes often live for many years with different combinations of diabetes-related complications. We aimed to quantify how complication duration and total complication burden affect mortality, using data from national registers.

METHODS

This study included 33 396 individuals with type 1 diabetes, registered in the Swedish National Diabetes Register at any time between 2001 and 2012. Each individual was followed and classified according to their time-updated diabetes-related complication status. The main outcomes were all-cause mortality, cardiovascular (CV) mortality and non-CV mortality. Poisson models were used to estimate the rate of these outcomes as a function of the time-updated complication duration.

RESULTS

Overall, 1748 of the 33 396 individuals died during 198 872 person-years of follow-up. Overall, the time-updated all-cause mortality rate ratio (MRR) was 2.25 [95% confidence interval (CI): 1.99-2.54] for patients with diabetic kidney disease, 0.98 (0.82-1.18) for patients with retinopathy and 4.00 (3.56-4.50) for patients with cardiovascular disease relative to individuals without complications. The excess rate was highest in the first period after a diagnosis of CVD, with an 8-fold higher mortality rate, and stabilized after some 5 years. After diagnosis of diabetic kidney disease, we observed an increase in all-cause mortality with an MRR of around 2 compared with individuals without diabetic kidney disease, which stabilized after few years.

CONCLUSIONS

In this cohort we show that duration of diabetes-related complications is an important determinant of mortality in type 1 diabetes, for example the MRR associated with CVD is highest in the first period after diagnosis of CVD. A stronger focus on time-updated information and thorough consideration of complication duration may improve risk stratification in routine clinical practice.

Motifs of Three HLA-DQ Amino Acid Residues (α44, β57, β135) Capture Full Association With the Risk of Type 1 Diabetes in DQ2 and DQ8 Children

HLA-DQA1 and -DQB1 are strongly associated with type 1 diabetes (T1D), and DQ8.1 and DQ2.5 are major risk haplotypes. Next-generation targeted sequencing of HLA-DQA1 and -DQB1 in Swedish newly diagnosed 1- to 18 year-old patients (n = 962) and control subjects (n = 636) was used to construct abbreviated DQ haplotypes, converted into amino acid (AA) residues, and assessed for their associations with T1D. A hierarchically organized haplotype (HOH) association analysis allowed 45 unique DQ haplotypes to be categorized into seven clusters. The DQ8/9 cluster included two DQ8.1 risk and the DQ9 resistant haplotypes, and the DQ2 cluster included the DQ2.5 risk and DQ2.2 resistant haplotypes. Within each cluster, HOH found residues α44Q (odds ratio [OR] 3.29, P = 2.38 * 10^-85) and β57A (OR 3.44, P = 3.80 * 10^-84) to be associated with T1D in the DQ8/9 cluster representing all ten residues (α22, α23, α44, α49, α51, α53, α54, α73, α184, β57) due to complete linkage disequilibrium (LD) of α44 with eight such residues. Within the DQ2 cluster and due to LD, HOH analysis found α44C and β135D to share the risk for T1D (OR 2.10, P = 1.96 * 10^-20). The motif "QAD" of α44, β57, and β135 captured the T1D risk association of DQ8.1 (OR 3.44, P = 3.80 * 10^-84), and the corresponding motif "CAD" captured the risk association of DQ2.5 (OR 2.10, P = 1.96 * 10^-20). Two risk associations were related to GAD65 autoantibody (GADA) and IA-2 autoantibody (IA-2A) but in opposite directions. CAD was positively associated with GADA (OR 1.56, P = 6.35 * 10^-8) but negatively with IA-2A (OR 0.59, P = 6.55 * 10^-11). QAD was negatively associated with GADA (OR 0.88; P = 3.70 * 10^-3) but positively with IA-2A (OR 1.64; P = 2.40 * 10^-14), despite a single difference at α44. The residues are found in and around anchor pockets 1 and 9, as potential T-cell receptor contacts, in the areas for CD4 binding and putative homodimer formation. The identification of three HLA-DQ AAs (α44, β57, β135) conferring T1D risk should sharpen functional and translational studies.

Geographical differences in cancer treatment and survival for patients with oesophageal and gastro-oesophageal junctional cancers

BACKGROUND

Only around one-quarter of patients with cancer of the oesophagus and the gastro-oesophageal junction (GOJ) undergo surgical resection. This population-based study investigated the rates of treatment with curative intent and resection, and their association with survival.

METHODS

Patients diagnosed with oesophageal and GOJ cancer between 2006 and 2015 in Sweden were identified from the National Register for Oesophageal and Gastric Cancer (NREV). The NREV was cross-linked with several national registries to obtain information on additional exposures. The annual proportion of patients undergoing treatment with curative intent and surgical resection in each county was calculated, and the counties divided into groups with low, intermediate and high rates. Treatment with curative intent was defined as definitive chemoradiation therapy or surgery, with or without neoadjuvant oncological treatment. Overall survival was analysed using a multilevel model based on county of residence at the time of diagnosis.

RESULTS

Some 5959 patients were included, of whom 1503 (25·2 per cent) underwent surgery. Median overall survival after diagnosis was 7·7, 8·8 and 11·1 months respectively in counties with low, intermediate and high rates of treatment with curative intent. Corresponding survival times for the surgical resection groups were 7·4, 9·3 and 11·0 months. In the multivariable analysis, a higher rate of treatment with curative intent (time ratio 1·17, 95 per cent c.i. 1·05 to 1·30; P < 0·001) and a higher resection rate (time ratio 1·24, 1·12 to 1·37; P < 0·001) were associated with improved survival after adjustment for relevant confounders.

CONCLUSION

Patients diagnosed in counties with higher rates of treatment with curative intent and higher rates of surgery had better survival.

Early Childhood Antibiotic Treatment for Otitis Media and Other Respiratory Tract Infections Is Associated With Risk of Type 1 Diabetes: A Nationwide Register-Based Study With Sibling Analysis

OBJECTIVE

The effect of early-life antibiotic treatment on the risk of type 1 diabetes is debated. This study assessed this question, applying a register-based design in children up to age 10 years including a large sibling-control analysis.

RESEARCH DESIGN AND METHODS

All singleton children (n = 797,318) born in Sweden between 1 July 2005 and 30 September 2013 were included and monitored to 31 December 2014. Cox proportional hazards models, adjusted for parental and perinatal characteristics, were applied, and stratified models were used to account for unmeasured confounders shared by siblings.

RESULTS

Type 1 diabetes developed in 1,297 children during the follow-up (median 4.0 years [range 0-8.3]). Prescribed antibiotics in the 1st year of life (23.8%) were associated with an increased risk of type 1 diabetes (adjusted hazard ratio [HR] 1.19 [95% CI 1.05-1.36]), with larger effect estimates among children delivered by cesarean section (P for interaction = 0.016). The association was driven by exposure to antibiotics primarily used for acute otitis media and respiratory tract infections. Further, we found an association of antibiotic prescriptions in pregnancy (22.5%) with type 1 diabetes (adjusted HR 1.15 [95% CI 1.00-1.32]). In general, sibling analysis supported these results, albeit often with statistically nonsignificant associations.

CONCLUSIONS

Dispensed prescription of antibiotics, mainly for acute otitis media and respiratory tract infections, in the 1st year of life is associated with an increased risk of type 1 diabetes before age 10 years, most prominently in children delivered by cesarean section.

Co-aggregation and heritability of organ-specific autoimmunity: a population-based twin study

OBJECTIVE

Co-aggregation of autoimmune diseases is common, suggesting partly shared etiologies. Genetic factors are believed to be important, but objective measures of environmental vs heritable influences on co-aggregation are absent. With a novel approach to twin studies, we aimed at estimating heritability and genetic overlap in seven organ-specific autoimmune diseases.

DESIGN

Prospective twin cohort study.

METHODS

We used a cohort of 110 814 twins to examine co-aggregation and heritability of Hashimoto's thyroiditis, atrophic gastritis, celiac disease, Graves' disease, type 1 diabetes, vitiligo and Addison's disease. Hazard ratios (HR) were calculated for twins developing the same or different disease as compared to their co-twin. The differences between monozygotic and dizygotic twin pairs were used to estimate the genetic influence on co-aggregation. Heritability for individual disorders was calculated using structural equational modeling adjusting for censoring and truncation of data.

RESULTS

Co-aggregation was more pronounced in monozygotic twins (median HR: 3.2, range: 2.2-9.2) than in dizygotic twins (median HR: 2.4, range: 1.1-10.0). Heritability was moderate for atrophic gastritis (0.38, 95% CI: 0.23-0.53) but high for all other diseases, ranging from 0.60 (95% CI: 0.49-0.71) for Graves' disease to 0.97 (95% CI: 0.91-1.00) for Addison's disease.

CONCLUSIONS

Overall, co-aggregation was more pronounced in monozygotic than in dizygotic twins, suggesting that disease overlap is largely attributable to genetic factors. Co-aggregation was common, and twins faced up to a ten-fold risk of developing diseases not present in their co-twin. Our results validate and refine previous heritability estimates based on smaller twin cohorts.

Prevalence and incidence of type 1 diabetes in Ireland: a retrospective cross-sectional study using a national pharmacy claims data from 2016

OBJECTIVES

The aim of this study is to estimate the prevalence and incidence of type 1 diabetes in the Irish population using a national pharmacy claims database in the absence of a national diabetes register.

DESIGN

National, population-based, retrospective, cross-sectional study.

SETTING

Community care with data available through the Health Service Executive Pharmacy Claims Reimbursement Scheme from 2011 to 2016.

PARTICIPANTS

Individuals with type 1 diabetes were identified by coprescription of insulin and glucometer test strips without any prolonged course (>12 months) of oral hypoglycaemic agents prior to commencing insulin. Those claiming prescriptions for long-acting insulin only, without any prandial insulin, were excluded from the analysis. Incidence was estimated based on the first claim for insulin in 2016, with no insulin use in the preceding 12 months.

MAIN OUTCOME MEASURES

Prevalence of type 1 diabetes in children (<18 years) and adults (≥18 years); incidence of type 1 diabetes in children (≤14 years) and adolescents and adults (>14 years).

RESULTS

There were 20 081 prevalent cases of type 1 diabetes in 2016. The crude prevalence was 0.42% (95% CI 0.42% to 0.43%). Most prevalent cases (n=17 053, 85%) were in adults with a prevalence of 0.48% (95% CI 0.47% to 0.48%). There were 1527 new cases of type 1 diabetes in 2016, giving an incidence rate of 32 per 100 000 population/year (95% CI 30.5 to 33.7). There was a significant positive linear trend for age, for prevalence (p<0.0001) and incidence (p=0.014). The prevalence and incidence were 1.2-fold and 1.3-fold higher in men than women, respectively. Significant variations in prevalence (p<0.0001) and incidence (p<0.001) between the different geographical regions were observed.

CONCLUSIONS

This study provides epidemiological estimates of type 1 diabetes across age groups in Ireland, with the majority of prevalent cases in adults. Establishing a national diabetes register is essential to enable updated epidemiological estimates of diabetes and for planning of services in Ireland.

Familial Coaggregation of Asthma and Type 1 Diabetes in Children

IMPORTANCE

The association between atopic and autoimmune disease, particularly asthma and type 1 diabetes, has been debated. Further understanding of the underlying factors associated with the comorbidity in children is warranted.

OBJECTIVES

To assess the bidirectional association between asthma and type 1 diabetes and examine the possibility of a shared risk for the diseases by studying their pattern of familial coaggregation.

DESIGN, SETTING, AND PARTICIPANTS

A birth cohort study of children born from January 1, 2001, and followed up until December 31, 2015, was performed. Population data were obtained from multiple national Swedish registers. A total of 1 347 901 singleton children, live-born in Sweden between January 1, 2001, and December 31, 2013, were identified, and children with incomplete data were excluded. The remaining 1 284 748 children were linked to their biological full siblings, maternal and paternal half-siblings, cousins, and half-cousins. Data analysis was conducted from April 1, 2019, to January 17, 2020.

MAIN OUTCOMES AND MEASURES

Cases of asthma and type 1 diabetes were defined using a combination of diagnoses and medication prescriptions found in the registers.

RESULTS

In the cohort of 1 284 748 children, 660 738 children (51.4%) were boys; 121 809 children (9.5%) had asthma, 3812 children (0.3%) had type 1 diabetes, and 494 children had both asthma and type 1 diabetes, representing 0.4% of all asthma or 13% of all type 1 diabetes. Mean (SD) age at diagnosis was 3.0 (2.8) years for children with asthma, and 5.9 (3.3) years for those with type 1 diabetes. Asthma and type 1 diabetes were associated within individuals (odds ratio, 1.15; 95% CI, 1.05-1.27). Children with asthma had an increased risk of subsequent type 1 diabetes (hazard ratio, 1.16; 95% CI, 1.06-1.27); however, subsequent asthma risk did not differ substantially among children with type 1 diabetes (hazard ratio, 0.92; 95% CI, 0.75-1.12). Siblings of individuals with asthma were at an increased risk of type 1 diabetes (odds ratio, 1.27; 95% CI, 1.13-1.42) and vice versa. The results remained positive after controlling for the direct association of one disease with the other.

CONCLUSIONS AND RELEVANCE

This study appears to provide evidence for co-occurrence, importance of sequential appearance, and coaggregation of asthma and type 1 diabetes in children and their siblings. The findings may suggest shared familial factors contributing to the associations. Knowledge of the nature of the association could be of importance in future clinical practice.

Gestational diabetes associated with incident diabetes in childhood and youth: a retrospective cohort study

BACKGROUND

Indicators of childhood- and youth-onset diabetes may be useful for early detection of diabetes; there is a known association between composite exposure of parental type 2 diabetes and gestational diabetes mellitus with childhood- and youth-onset diabetes. We examined associations between gestational diabetes mellitus and incidence of childhood- and youth-onset diabetes in offspring.

METHODS

Using public health insurance administrative databases from Quebec, Canada, we randomly selected singleton live births with maternal gestational diabetes mellitus (1990-2007) and matched them 1:1 with singleton live births without gestational diabetes mellitus. Follow-up was to Mar. 31, 2012. We examined associations of diabetes in offspring with maternal gestational diabetes mellitus through unadjusted and adjusted Cox proportional hazards models. In secondary analyses, we separately considered age groups ranging from birth to age 12 years, and age 12 to 22 years.

RESULTS

Incidence of pediatric diabetes (per 10 000 person-years) was higher in offspring born to mothers with gestational diabetes mellitus (4.52, 95% confidence interval [CI] 4.47-4.57) than in mothers without gestational diabetes mellitus (2.4, 95% CI 2.37-2.46). In an adjusted Cox proportional hazards model, maternal gestational diabetes mellitus was associated with development of pediatric diabetes overall (birth to age 22 yr: hazard ratio [HR] 1.77, 95% CI 1.41-2.22), during childhood (birth to age 12 yr: HR 1.43, 95% CI 1.09-1.89), and in youth (age 12 to 22 yr: HR 2.53, 95% CI 1.67-3.85).

INTERPRETATION

Gestational diabetes mellitus is associated with incident diabetes in offspring during childhood and adolescence. Future studies are needed to examine longer-term outcomes in patients with pediatric diabetes with a maternal history of gestational diabetes mellitus, to ascertain how they compare with other patients with childhood- or youth-onset diabetes, in terms of disease severity and outcomes.

Correlating the global increase in type 1 diabetes incidence across age groups with national economic prosperity: A systematic review

BACKGROUND

The global epidemiology of type 1 diabetes (T1D) is not yet well known, as no precise data are available from many countries. T1D is, however, characterized by an important variation in incidences among countries and a dramatic increase of these incidences during the last decades, predominantly in younger children. In the United States and Europe, the increase has been associated with the gross domestic product (GDP) per capita. In our previous systematic review, geographical variation of incidence was correlated with socio-economic factors.

AIM

To investigate variation in the incidence of T1D in age categories and search to what extent these variations correlated with the GDP per capita.

METHODS

A systematic review was performed to retrieve information about the global incidence of T1D among those younger than 14 years of age. The study was carried out according to the PRISMA recommendations. For the analysis, the incidence was organized in the periods: 1975-1999 and 2000-2017. We searched the incidence of T1D in the age-groups 0-4, 5-9 and 10-14. We compared the incidences in countries for which information was available for the two periods. We obtained the GDP from the World Bank. We analysed the relationship between the incidence of T1D with the GDP in countries reporting data at the national level.

RESULTS

We retrieved information for 84 out of 194 countries around the world. We found a wide geographic variation in the incidence of T1D and a worldwide increase during the two periods. The largest contribution to this increase was observed in the youngest group of children with T1D, with a relative increase of almost double when comparing the two periods (P value = 2.5 × e^-5). Twenty-six countries had information on the incidence of T1D at the national level for the two periods. There was a positive correlation between GDP and the incidence of T1D in both periods (Spearman correlation = 0.52 from 1975-1999 and Spearman correlation = 0.53 from 2000-2017).

CONCLUSION

The incidence increase was higher in the youngest group (0-4 years of age), and the highest incidences of T1D were found in wealthier countries.

The heterogeneous pathogenesis of type 1 diabetes mellitus

Type 1 diabetes mellitus (T1DM) results from the destruction of pancreatic β-cells that is mediated by the immune system. Multiple genetic and environmental factors found in variable combinations in individual patients are involved in the development of T1DM. Genetic risk is defined by the presence of particular allele combinations, which in the major susceptibility locus (the HLA region) affect T cell recognition and tolerance to foreign and autologous molecules. Multiple other loci also regulate and affect features of specific immune responses and modify the vulnerability of β-cells to inflammatory mediators. Compared with the genetic factors, environmental factors that affect the development of T1DM are less well characterized but contact with particular microorganisms is emerging as an important factor. Certain infections might affect immune regulation, and the role of commensal microorganisms, such as the gut microbiota, are important in the education of the developing immune system. Some evidence also suggests that nutritional factors are important. Multiple islet-specific autoantibodies are found in the circulation from a few weeks to up to 20 years before the onset of clinical disease and this prediabetic phase provides a potential opportunity to manipulate the islet-specific immune response to prevent or postpone β-cell loss. The latest developments in understanding the heterogeneity of T1DM and characterization of major disease subtypes might help in the development of preventive treatments.

Early Clinical Indicators of Addison Disease in Adults With Type 1 Diabetes: A Nationwide, Observational, Cohort Study

CONTEXT

Patients with type 1 diabetes mellitus (T1DM) have an increased risk of Addison disease (AD) development, but prediction of those at risk is not possible.

OBJECTIVE

To determine whether there are early clinical indicators that may denote the development of AD in adults with T1DM.

DESIGN

Observational, matched-cohort study.

SETTING

Patient data from Swedish national registries [National Diabetes Register (NDR), Inpatient Register, and Prescription Drug Register].

PARTICIPANTS

All patients with T1DM diagnosed with concomitant AD (n = 66) among the 36,514 adult patients with T1DM in the NDR between 1998 and 2013. Each case was matched to five controls with T1DM alone (n = 330).

MAIN OUTCOME MEASURES

Clinical data and drug prescriptions were assessed prior to baseline (inclusion into the study) and prior to AD diagnosis. Analysis of covariance and estimated group proportions were used for comparisons.

RESULTS

Prior to baseline, cases had a higher frequency of thyroid/antithyroid drug prescription than controls (9.1% vs 1.8%). Prior to AD diagnosis, cases had higher frequencies of diabetic retinopathy (12.1% vs 2.1%), infections requiring hospital admission (16.7% vs 2.1%), thyroid/antithyroid drug prescription (28.8% vs 7.0%), and glucagon prescription (18.2% vs 6.4%). There was no difference in glycated Hb between the groups prior to baseline or prior to AD diagnosis.

CONCLUSIONS

These data suggest that medical treatment of thyroid disease, a severe infection, and glucagon prescription for severe hypoglycemia should raise the suspicion of AD development in adults with T1DM. Development of diabetic retinopathy might also be associated with glucocorticoid deficiency and the development of AD among patients with T1DM.

Decreasing Cumulative Incidence of End-Stage Renal Disease in Young Patients With Type 1 Diabetes in Sweden: A 38-Year Prospective Nationwide Study

OBJECTIVE

Diabetic nephropathy is a serious complication of type 1 diabetes. Recent studies indicate that end-stage renal disease (ESRD) incidence has decreased or that the onset of ESRD has been postponed; therefore, we wanted to analyze the incidence and time trends of ESRD in Sweden.

RESEARCH DESIGN AND METHODS

In this study, patients with duration of type 1 diabetes >14 years and age at onset of diabetes 0-34 years were included. Three national diabetes registers were used: the Swedish Childhood Diabetes Register, the Diabetes Incidence Study in Sweden, and the National Diabetes Register. The Swedish Renal Registry, a national register on renal replacement therapy, was used to identify patients who developed ESRD.

RESULTS

We found that the cumulative incidence of ESRD in Sweden was low after up to 38 years of diabetes duration (5.6%). The incidence of ESRD was lower in patients with type 1 diabetes onset in 1991-2001 compared with onset in 1977-1984 and 1985-1990, independent of diabetes duration.

CONCLUSIONS

The risk of developing ESRD in Sweden in this population is still low and also seems to decrease with time.

Early Occurrence Cases of Diabetes Mellitus: Clinical Picture in Two Major Tertiary Care Hospitals in India

INTRODUCTION

Type 1 diabetes mellitus (T1D) is one of the most common endocrine diseases in childhood. However, very limited information is available on this disease.

OBJECTIVES

This study was done to assess risk factors, clinical features and management practices in T1D patients.

METHODS

A review of records of 39 T1D cases admitted over the past five years in two hospitals was done.

RESULTS

The mean age at diagnosis among males (n=21) was 19.9±10.3 years and among females (n=18) was 12.3±7.5 years (t=2.614, p=0.013). Mean age at diagnosis of patients who were underweight (n=7) was 9.9±4.4 years, compared to 17.8±10.1 years among patients (n=32) with normal or overweight status (t=2.028, p=0.05). The family history of T1D was present among 7(18.0%) cases. The most common symptoms among the cases were fatigue 22(56.4%), polyuria 19(48.7%) and polydipsia 18(46.1%). The most common sign was weight loss 27(69.2%). The most common complications were diabetic nephropathy and skin infections seen each among 10(25.6%) cases. Mean duration of T1D was significantly more among patients with diabetic nephropathy (p<0.001), compared to those without. Mean HbA1c value among patients was 12.9±2.7. It was significantly more among patients with Diabetic Ketoacidosis (DKA) (p=0.012). A short-acting insulin was used in the management of T1D among 59.5% cases. The outcome of the management showed a loss of one patient who developed DKA.

CONCLUSION

Routine growth monitoring and blood glucose analysis is required among T1D cases. The present study provides a database of risk factors, clinical features, and management practices among patients with T1D in this region and addresses several issues important to both patients and their care providers.

Latent Autoimmune Diabetes in Adults: A Review on Clinical Implications and Management

Latent autoimmune diabetes in adults (LADA) is a heterogeneous disease characterized by a less intensive autoimmune process and a broad clinical phenotype compared to classical type 1 diabetes mellitus (T1DM), sharing features with both type 2 diabetes mellitus (T2DM) and T1DM. Since patients affected by LADA are initially insulin independent and recognizable only by testing for islet-cell autoantibodies, it could be difficult to identify LADA in clinical setting and a high misdiagnosis rate still remains among patients with T2DM. Ideally, islet-cell autoantibodies screening should be performed in subjects with newly diagnosed T2DM, ensuring a closer monitoring of those resulted positive and avoiding treatment of hyperglycaemia which might increase the rate of β-cells loss. Thus, since the autoimmune process in LADA seems to be slower than in classical T1DM, there is a wider window for new therapeutic interventions that may slow down β-cell failure. This review summarizes the current understanding of LADA, by evaluating data from most recent studies, the actual gaps in diagnosis and management. Finally, we critically highlight and discuss novel findings and future perspectives on the therapeutic approach in LADA.

Excess mortality and cardiovascular disease in young adults with type 1 diabetes in relation to age at onset: a nationwide, register-based cohort study

BACKGROUND

People with type 1 diabetes are at elevated risk of mortality and cardiovascular disease, yet current guidelines do not consider age of onset as an important risk stratifier. We aimed to examine how age at diagnosis of type 1 diabetes relates to excess mortality and cardiovascular risk.

METHODS

We did a nationwide, register-based cohort study of individuals with type 1 diabetes in the Swedish National Diabetes Register and matched controls from the general population. We included patients with at least one registration between Jan 1, 1998, and Dec 31, 2012. Using Cox regression, and with adjustment for diabetes duration, we estimated the excess risk of all-cause mortality, cardiovascular mortality, non-cardiovascular mortality, acute myocardial infarction, stroke, cardiovascular disease (a composite of acute myocardial infarction and stroke), coronary heart disease, heart failure, and atrial fibrillation. Individuals with type 1 diabetes were categorised into five groups, according to age at diagnosis: 0-10 years, 11-15 years, 16-20 years, 21-25 years, and 26-30 years.

FINDINGS

27 195 individuals with type 1 diabetes and 135 178 matched controls were selected for this study. 959 individuals with type 1 diabetes and 1501 controls died during follow-up (median follow-up was 10 years). Patients who developed type 1 diabetes at 0-10 years of age had hazard ratios of 4·11 (95% CI 3·24-5·22) for all-cause mortality, 7·38 (3·65-14·94) for cardiovascular mortality, 3·96 (3·06-5·11) for non-cardiovascular mortality, 11·44 (7·95-16·44) for cardiovascular disease, 30·50 (19·98-46·57) for coronary heart disease, 30·95 (17·59-54·45) for acute myocardial infarction, 6·45 (4·04-10·31) for stroke, 12·90 (7·39-22·51) for heart failure, and 1·17 (0·62-2·20) for atrial fibrillation. Corresponding hazard ratios for individuals who developed type 1 diabetes aged 26-30 years were 2·83 (95% CI 2·38-3·37) for all-cause mortality, 3·64 (2·34-5·66) for cardiovascular mortality, 2·78 (2·29-3·38) for non-cardiovascular mortality, 3·85 (3·05-4·87) for cardiovascular disease, 6·08 (4·71-7·84) for coronary heart disease, 5·77 (4·08-8·16) for acute myocardial infarction, 3·22 (2·35-4·42) for stroke, 5·07 (3·55-7·22) for heart failure, and 1·18 (0·79-1·77) for atrial fibrillation; hence the excess risk differed by up to five times across the diagnosis age groups. The highest overall incidence rate, noted for all-cause mortality, was 1·9 (95% CI 1·71-2·11) per 100 000 person-years for people with type 1 diabetes. Development of type 1 diabetes before 10 years of age resulted in a loss of 17·7 life-years (95% CI 14·5-20·4) for women and 14·2 life-years (12·1-18·2) for men.

INTERPRETATION

Age at onset of type 1 diabetes is an important determinant of survival, as well as all cardiovascular outcomes, with highest excess risk in women. Greater focus on cardioprotection might be warranted in people with early-onset type 1 diabetes.

FUNDING

Swedish Heart and Lung Foundation.

Latent Autoimmune Diabetes in Adults: Current Status and New Horizons

Autoimmune diabetes is a heterogeneous disease which can arise at any age. Subjects with adult-onset autoimmune diabetes who do not necessitate insulin-therapy for at least 6 months after diagnosis are demarcated as having latent autoimmune diabetes in adults (LADA). This condition is more heterogeneous than young-onset autoimmune diabetes and shares clinical and metabolic characteristics with both type 2 and type 1 diabetes. Patients with LADA are considered by having highly variable β-cell destruction, different degrees of insulin resistance and heterogeneous titre and pattern of islet autoantibody, suggesting different pathophysiological pathways partially explaining the heterogeneous phenotypes of LADA. To date the heterogeneity of LADA does not allow to establish a priori treatment algorithm and no specific guidelines for LADA therapy are available. These subjects are mostly treated as affected by type 2 diabetes, a factor that might lead to the progression to insulin-dependency quickly. A personalised medicine approach is necessary to attain optimal metabolic control and preserve β-cell function to decrease the risk of long-term diabetes complications. Recent data concerning the use of oral antidiabetic agents as dipeptidyl peptidase 4 inhibitors and glucagon-like peptide 1 receptor agonists indicate up-and-coming results in term of protect C-peptide levels and improving glycaemic control. This review summarises current knowledge on LADA, emphasising controversies regarding its pathophysiology and clinical features. Moreover, we discuss data available about novel therapeutic approaches that can be considered for prevention of β-cell loss in LADA.

Type 1 Diabetes in Parents and Risk of Attention Deficit/Hyperactivity Disorder in Offspring: A Population-Based Study in Sweden

OBJECTIVE

To explore whether a family history of type 1 diabetes (T1D) is associated with an increased incidence of attention deficit/hyperactivity disorder (ADHD) in offspring.

RESEARCH DESIGN AND METHODS

Individuals with T1D were identified from the nationwide Swedish National Hospital Discharge Register and Swedish Outpatient Register in Sweden and were linked to the Swedish Multi-Generation Register to identify their offspring. Cox regression was used to calculate the hazard ratio (HR) of ADHD in offspring of patients with T1D compared with the general population.

RESULTS

A total of 15,615 individuals were born after their parents were diagnosed with T1D. After a set of confounding factors was controlled for, offspring of T1D patients had a significantly increased risk of ADHD with an HR of 1.29 (95% CI 1.15-1.42). Maternal T1D was associated with an enhanced risk of ADHD (HR 1.35 [95% CI 1.18-1.55]) compared with paternal T1D (HR 1.20 [95% CI 1.03-1.41]), but the difference was not statistically significant.

CONCLUSIONS

In this retrospective cohort study, we found that a parental history of T1D was associated with a 29% increased risk of being diagnosed with ADHD. However, the underlying mechanisms need to be explored in future studies.

Short-term progression of cardiometabolic risk factors in relation to age at type 2 diabetes diagnosis: a longitudinal observational study of 100,606 individuals from the Swedish National Diabetes Register

AIMS/HYPOTHESIS

The reasons underlying a greater association of premature mortality with early-onset type 2 diabetes relative to late-onset disease are unclear. We evaluated the clinical characteristics at type 2 diabetes diagnosis and the broad trajectories in cardiometabolic risk factors over the initial years following diagnosis in relation to age at diagnosis.

METHODS

Our cohort consisted of 100,606 individuals with newly diagnosed type 2 diabetes enrolled in the Swedish National Diabetes Register from 2002 to 2012. The average follow-up time was 2.8 years. Analyses were performed using a linear mixed-effects model for continuous risk factors and a mixed generalised linear model with a logistic link function for dichotomous risk factors.

RESULTS

The individuals diagnosed at the youngest age (18-44 years) were more often male and had the highest BMI (mean of 33.4 kg/m²) at diagnosis and during follow-up compared with all other groups (those diagnosed at 45-59 years, 60-74 years and ≥75 years; p < 0.05), being ~5 kg/m² higher than the oldest group. Although HbA_1c patterns were similar between all age groups, there was a difference of about 5 mmol/mol (0.45%) between the two groups at 8 years post-diagnosis (p < 0.05). Additionally, individuals diagnosed younger had ~0.7 mmol/l higher triacylglycerol, and ~0.2 mmol/l lower HDL-cholesterol levels at diagnosis relative to the oldest group. Such differences continued for several years post diagnosis. Yet, although more of these younger individuals were receiving oral glucose-lowering agents, other cardioprotective therapies were prescribed less often in this group. Differences in BMI, blood glucose and lipid levels remained with adjustment for potential confounders, including marital status, education and country of birth, and, where relevant, differential treatments by age, and in those with at least 5 years of follow-up.

CONCLUSIONS/INTERPRETATION

Individuals who develop type 2 diabetes at a younger age are more frequently obese, display a more adverse lipid profile, have higher HbA_1c and a faster deterioration in glycaemic control compared with individuals who develop diabetes later in life. These differences largely remain for several years after diagnosis and support the notion that early-onset type 2 diabetes may be a more pathogenic condition than late-onset disease.

Using Routine Data Sources to Feed an Immunization Information System for High-Risk Patients-A Pilot Study

Background

Vaccine-preventable diseases among high-risk patients are a public health priority in high-income countries. Most national immunization programs have included vaccination recommendations for these population groups but they remain hard-to-reach and coverage data are poorly available. In a pilot study, we developed and tested an automated approach for identifying individuals with underlying medical conditions to feed an immunization information system (IIS).

Methods

We reviewed published recommendations on medical conditions that indicate vaccination against influenza, pneumococcal disease, meningococcal disease, hepatitis A, and hepatitis B. For each medical condition, we identified the International Classification of Diseases, Ninth Revision, Clinical Modification diagnosis and procedure codes, the user fee exempt codes and the Anatomical Therapeutic Chemical Classification System codes and we reported these data in correspondence tables. Using these tables, we extracted three lists of patients recorded in three current data sources between 2001 and 2010 in the Apulia region of Italy: the hospital discharge registry, the user fee exempt registry, and the drug prescription registry. Using a unique personal identification number, we linked these three lists of patients with the regional IIS (2012 database), obtaining a list of patients with chronic diseases eligible for vaccination. We tested completeness, sensitivity, and positive predictive value (PPV) of this approach by asking a sample of 28 general practitioners (GPs) to evaluate the matching between a sublist of patients with clinical recommendations for influenza vaccination and the GPs individual subjects medical records.

Results

We included a total of 1,204,496 subjects with underlying medical conditions eligible to receive any of the aforementioned vaccinations. Of these, 9% were identified in all three data sources, 18% in two sources, and 73% in one source. The completeness of this automated process in identifying GPs high-risk patients eligible for influenza vaccination was 88.9% [95% confidence intervals (95% CI): 88.1–89.8%], with a sensitivity of 69.2% (95% CI: 67.7–70.6%) and a PPV of 85.7% (95% CI: 84.4–86.8%).

Conclusion

The high completeness of the methodology used for identifying high-risk patients in current data sources encouraged us to apply this approach for feeding the regional IIS.

Achieving Good Glycemic Control Early After Onset of Diabetes: A Cost-Effectiveness Analysis in Patients with Type 1 Diabetes in Sweden

INTRODUCTION

Sweden has amongst the highest incidence rates of type 1 diabetes (T1D) in Europe. The high incidence and chronic nature of T1D result in high prevalence and economic burden. Improving glycemic control reduces the incidence of microvascular complications, which in turn reduces medical costs. The present study aimed to quantify the reductions in cost and improvements in quality-adjusted life expectancy with varying reductions in HbA1c in the T1D population.

METHODS

The IQVIA CORE Diabetes Model was used to simulate a typical Swedish population of patients with T1D experiencing HbA1c reductions from 0.1% to 0.8% (in 0.1% increments) from 7.9% at baseline. Analyses were conducted in simulated cohorts based on data from the Swedish National Diabetes Register (NDR) and in subgroups by sex, smoking status, and body mass index (BMI), with different sets of quality-of-life utilities included. Generalized least squares (GLS) models were used to test for significant differences between subgroups. Analyses were also performed to investigate the effect of the duration of HbA1c control. Analyses were run over 50 years and outcomes discounted at 3% per annum.

RESULTS

In the reference case analysis, reducing HbA1c lowered the incidence of microvascular and macrovascular complications and improved quality-adjusted life expectancy. GLS models identified a significantly larger benefit of reducing HbA1c in women over men, but found no significant differences in the magnitude of quality of life improvements with decreasing HbA1c when segregating by smoking status or BMI.

CONCLUSIONS

Reducing HbA1c in a population with T1D would reduce the incidence of microvascular complications, improve life expectancy and quality of life. Larger quality-of-life benefits were observed in younger and female adult patients, but no notable differences were observed in the benefits of glycemic control in smokers versus non-smokers or in patients with low or high BMI.

FUNDING

Novo Nordisk Scandinavia AB, Malmö, Sweden.

Incidence, prevalence and seasonal onset variation of Addison's disease among persons with type 1 diabetes mellitus: nationwide, matched cohort studies

OBJECTIVES

We determined the incidence and prevalence of Addison's disease (AD) among persons with or without type 1 diabetes mellitus (T1DM) in nationwide, matched cohort studies.

METHODS

Persons with T1DM were identified from the Swedish National Diabetes Register and each was matched for age, sex, year and county to five controls randomly selected from the general population. Persons with AD were identified from the Swedish National Inpatient Register. Baseline demographics and seasonal onset variation of AD were presented by descriptive statistics. Prevalence and incidence were estimated by proportions and incidence rates, respectively. Times to AD were analyzed using the Cox proportional hazard model.

RESULTS

Between 1998 and 2013, 66 persons with T1DM were diagnosed with AD at a mean age (s.d.) of 36.4 (13.0) years among 36 514 persons with T1DM, while 32 were diagnosed with AD at a mean age of 42.7 (15.2) years among 182 570 controls. The difference in mean age at diagnosis of AD between the groups was 6.3 years (P value = 0.036). The incidence of AD for a person with or without T1DM was therefore 193 and 18 per million person-years, respectively. The adjusted relative risk increase of developing AD in T1DM was 10.8 (95% CI: 7.1-16.5). The highest incidence of AD was observed during February-March and September-October. The prevalence of AD in persons with or without T1DM in December 2012 was 3410 and 208 per million, respectively. The odds ratio for AD in persons with T1DM vs controls was 16.5 (95% CI: 11.1-24.5).

CONCLUSION

The risk to develop AD among persons with T1DM is more than 10 times higher than in persons without T1DM. Persons with T1DM develop AD at a younger age. The incidence of AD may have a seasonal pattern.

Gestational respiratory infections interacting with offspring HLA and CTLA-4 modifies incident β-cell autoantibodies

β-cell autoantibodies against insulin (IAA), GAD65 (GADA) and IA-2 (IA-2A) precede onset of childhood type 1 diabetes (T1D). Incidence of the first appearing β-cell autoantibodies peaks at a young age and is patterned by T1D-associated genes, suggesting an early environmental influence. Here, we tested if gestational infections and interactions with child's human leukocyte antigen (HLA) and non-HLA genes affected the appearance of the first β-cell autoantibody. Singletons of mothers without diabetes (n = 7472) with T1D-associated HLA-DR-DQ genotypes were prospectively followed quarterly through the first 4 years of life, then semiannually until age 6 years, using standardized autoantibody analyses. Maternal infections during pregnancy were assessed via questionnaire 3-4.5 months post-delivery. Polymorphisms in twelve non-HLA genes associated with the first appearing β-cell autoantibodies were included in a Cox regression analysis. IAA predominated as the first appearing β-cell autoantibody in younger children (n = 226, median age at seroconversion 1.8 years) and GADA (n = 212; 3.2 years) in children aged ≥2 years. Gestational infections were not associated with the first appearing β-cell autoantibodies overall. However, gestational respiratory infections (G-RI) showed a consistent protective influence on IAA (HR 0.64, 95% CI 0.45-0.91) among CTLA4-(AG, GG) children (G-RI*CTLA4 interaction, p = 0.002). The predominant associations of HLA-DR-DQ 4-8/8-4 with IAA and HLA-DR-DQ 3-2/3-2 with GADA were not observed if a G-RI was reported (G-RI*HLA-DR-DQ interaction, p = 0.03). The role of G-RI may depend on offspring HLA and CTLA-4 alleles and supports a bidirectional trigger for IAA or GADA as a first appearing β-cell autoantibody in early life.

Outcomes of Coronary Artery Bypass Graft Surgery Versus Percutaneous Coronary Intervention in Patients Aged 18-45 Years with Diabetes Mellitus

BACKGROUND

Debate on treatment for young patients with coronary artery disease still exists. This study aimed to investigate the intermediate- and long-term outcomes between coronary artery bypass grafting (CABG) and percutaneous coronary intervention (PCI) in patients aged 18-45 years with diabetes mellitus (DM).

METHODS

Between January 2006 and March 2016, a total of 2018 DM patients aged 18-45 years including 517 cases of CABG and 1501 cases of PCI were enrolled in the study. Using propensity score matching (PSM), 406 patients were matched from each group. The intermediate- and long-term data were collected. The primary end point of this study was long-term death. The secondary end points included long-term major adverse cardiovascular and cerebrovascular events (MACCEs), stroke, angina, myocardial infarction (MI), and repeat revascularization.

RESULTS

Before PSM, the in-hospital mortality was 1.2% in the CABG group and 0.1% in the PCI group, with statistically significant difference (P < 0.0001). The 10-year follow-up outcomes including long-term survival rate and freedom from MACCEs were better in the CABG group than those in the PCI group (97.3% vs. 94.5%, P = 0.0072; 93.2% vs. 86.3%, P < 0.0001), but CABG group was associated with lower freedom from stoke compared to PCI group (94.2% vs. 97.5%, P = 0.0059). After propensity score-matched analysis, these findings at 10-year follow-up were also confirmed. Freedom from MACCEs was higher in CABG group compared to PCI group, but no significant difference was observed (93.1% vs. 89.2%, P = 0.0720). The freedom from recurrent MI was significantly higher in CABG patients compared with PCI patients (95.6% vs. 92.5%, P = 0.0260). Furthermore, CABG was associated with a higher rate of long-term survival rate than PCI (97.5% vs. 94.6%, P = 0.0403). There was no significant difference in the freedom from stroke between CABG and PCI groups (95.3% vs. 97.3%, P = 0.9385). The hospital cost was greater for CABG (13,936 ± 4480 US dollars vs. 10,926 ± 7376 US dollars, P < 0.0001).

CONCLUSIONS

In DM patients aged 18-45 years, the cumulative survival rate, and freedom from MI and repeat revascularization for CABG were superior to those of PCI. However, a better trend to avoid stroke was observed with PCI.

Trends of childhood diabetes in Southern Thailand: 20-year experience in a tertiary medical center

BACKGROUND

The incidence and/or prevalence of both childhood diabetes and the percent of type 2 diabetes mellitus (T2DM) cases in children and young adolescents have been increasing worldwide. This study aimed to examine the 20-year trends of childhood diabetes in a single tertiary medical center in Southern Thailand.

METHODS

The medical records of pediatric diabetic patients, aged 0-15 years, diagnosed at Songklanagarind Hospital from 1995 to 2014 were retrospectively reviewed.

RESULTS

During the 20-year period, 156 children were diagnosed with DM: 99 (63.4%) with T1DM, 43 (27.6%) with T2DM, 2 (1.3%) with neonatal diabetes, and 12 (7.7%) with secondary diabetes. The estimated incidence of new patients with diabetes per 100 000 per year doubled from 0.12 in 1995-2000, to 0.24-0.28 in 2001-2004, and further increased to 0.39-0.48 in 2005-2012 and 0.59-0.64 in 2013-2014; and also the proportion of T2DM cases increased from 10%-15% during 1995-2003 to 25%-30% during 2004-2008, and 35%-40% during 2009-2014. At the time of diagnosis, the fasting plasma glucose and glycated hemoglobin levels were significantly greater in T1DM than T2DM patients while the lipid profiles were more abnormal in T2DM than T1DM patients.

CONCLUSIONS

The estimated incidences of both T1DM and T2DM in pediatric patients have increased markedly over the 20-year period, and also the percentage of T2DM cases, from 10%-15% in 1995 to 35%-40% in 2014.

Building and validating a prediction model for paediatric type 1 diabetes risk using next generation targeted sequencing of class II HLA genes

AIM

It is of interest to predict possible lifetime risk of type 1 diabetes (T1D) in young children for recruiting high-risk subjects into longitudinal studies of effective prevention strategies.

METHODS

Utilizing a case-control study in Sweden, we applied a recently developed next generation targeted sequencing technology to genotype class II genes and applied an object-oriented regression to build and validate a prediction model for T1D.

RESULTS

In the training set, estimated risk scores were significantly different between patients and controls (P = 8.12 × 10^-92 ), and the area under the curve (AUC) from the receiver operating characteristic (ROC) analysis was 0.917. Using the validation data set, we validated the result with AUC of 0.886. Combining both training and validation data resulted in a predictive model with AUC of 0.903. Further, we performed a "biological validation" by correlating risk scores with 6 islet autoantibodies, and found that the risk score was significantly correlated with IA-2A (Z-score = 3.628, P < 0.001). When applying this prediction model to the Swedish population, where the lifetime T1D risk ranges from 0.5% to 2%, we anticipate identifying approximately 20 000 high-risk subjects after testing all newborns, and this calculation would identify approximately 80% of all patients expected to develop T1D in their lifetime.

CONCLUSION

Through both empirical and biological validation, we have established a prediction model for estimating lifetime T1D risk, using class II HLA. This prediction model should prove useful for future investigations to identify high-risk subjects for prevention research in high-risk populations.

Adult-onset autoimmune diabetes: current knowledge and implications for management

Adult-onset autoimmune diabetes is a heterogeneous disease that is characterized by a reduced genetic load, a less intensive autoimmune process and a mild metabolic decompensation at onset compared with young-onset type 1 diabetes mellitus (T1DM). The majority of patients with adult-onset autoimmune diabetes do not require insulin treatment for at least 6 months after diagnosis. Such patients are defined as having latent autoimmune diabetes in adults (LADA), which is distinct from classic adult-onset T1DM. The extensive heterogeneity of adult-onset autoimmune diabetes is apparent beyond the distinction between classic adult-onset T1DM and LADA. LADA is characterized by genetic, phenotypic and humoral heterogeneity, encompassing different degrees of insulin resistance and autoimmunity; this heterogeneity is probably a result of different pathological mechanisms, which have implications for treatment. The existence of heterogeneous phenotypes in LADA makes it difficult to establish an a priori treatment algorithm, and therefore, a personalized medicine approach is required. In this Review, we discuss the current understanding and gaps in knowledge regarding the pathophysiology and clinical features of adult-onset autoimmune diabetes and highlight the similarities and differences with classic T1DM and type 2 diabetes mellitus.

Comorbidity does not predict long-term mortality after total hip arthroplasty

Background and purpose - In-hospital death following total hip arthroplasty (THA) is related to comorbidity. The long-term effect of comorbidity on all-cause mortality is, however, unknown for this group of patients and it was investigated in this study. Patients and methods - We used data from the Swedish Hip Arthroplasty Register, linked to the National Patient Register from the National Board of Health and Welfare, for patients operated on with THA in 1999-2012. We identified 120,836 THAs that could be included in the study. We evaluated the predictive power of the Charlson and Elixhauser comorbidity indices on mortality, using concordance indices calculated after 5, 8, and 14 years after THA. Results - All comorbidity indices performed poorly as predictors, in fact worse than a base model with age and sex only. Elixhauser was, however, the least bad choice and it predicted mortality with concordance indices 0.59, 0.58, and 0.56 for 5, 8, and 14 years after THA. Interpretation - Comorbidity indices are poor predictors of long-term mortality after THA.

Dog Exposure During the First Year of Life and Type 1 Diabetes in Childhood

IMPORTANCE

The association between early exposure to animals and type 1 diabetes in childhood is not clear.

OBJECTIVE

To determine whether exposure to dogs during the first year of life is associated with the development of type 1 diabetes in childhood.

DESIGN, SETTING, AND PARTICIPANTS

A nationwide cohort study utilizing high-quality Swedish national demographic and health registers was conducted. A total of 840 593 children born in Sweden from January 1, 2001, to December 31, 2010, were evaluated. Type 1 diabetes was identified using diagnosis codes from hospitals and dispensed prescriptions of insulin. Cox proportional hazards regression models were used to assess the association between exposure to dogs and risk of type 1 diabetes in childhood. The possible association was further investigated by performing dose-response and breed group-specific analyses. The cohort was followed up until September 30, 2012. Data analysis was conducted from October 15, 2015, to February 8, 2017.

EXPOSURES

Having a parent who was registered as a dog owner during the child's first year of life.

MAIN OUTCOMES AND MEASURES

Childhood-onset type 1 diabetes.

RESULTS

Of the 840 593 children reviewed, 408 272 (48.6%) were girls; mean (SD) age at diagnosis of type 1 diabetes was 5.1 (2.6) years. Dog exposure was identified in 102 035 children (12.1%). Follow-up started at age 1 year, and the children were followed up for as long as 10.7 years (median, 5.5 years). During follow-up, 1999 children developed type 1 diabetes. No association was found between exposure to dogs (adjusted hazard ratio [HR], 1.00; 95% CI, 0.86-1.16) and type 1 diabetes in childhood. The size of the dog (adjusted HR per 10-cm increase in height, 0.96; 95% CI, 0.86-1.06) or number of dogs in the household (1 dog: adjusted HR, 1.07; 95% CI, 0.91-1.26; 2 dogs: 0.79; 95% CI, 0.54-1.15; ≥3 dogs: 0.50; 95% CI, 0.23-1.12; compared with nonexposed children) also was not associated with type 1 diabetes risk. An analysis of children whose parent had type 1 diabetes (210 events) yielded an adjusted HR of 0.71 (95% CI, 0.43-1.17) for dog exposure.

CONCLUSIONS AND RELEVANCE

In a nationwide study, no evidence supporting an association of register-derived measures of dog exposure with childhood type 1 diabetes was identified.